A zinc secondary battery gel polymer electrolyte and preparation thereof, zinc secondary battery

Abstract

The present application relates to a kind of zinc secondary battery gel polymer electrolyte and its preparation, zinc secondary battery, which includes zinc salt, organic solvent, polymer and filler.Compared with prior art, the polymer gel electrolyte involved in the present application solves the problem of thermodynamic instability of zinc ion battery interface, eliminates the interface side reaction;Significantly improve the zinc ion transfer number;While regulating the metal zinc nucleation and growth mechanism, the formation of large dendrite is inhibited, the cycle life of metal zinc and zinc ion battery is greatly improved, and the practical value is high.

Description

Technical Field

[0001] This invention belongs to the field of zinc secondary battery technology, and relates to a zinc secondary battery gel polymer electrolyte and its preparation, and zinc secondary batteries. Background Technology

[0002] With the rapid development of portable electronic devices, smart grid storage, and electric vehicles, the demand for high-energy-density rechargeable batteries is constantly increasing. Among various metal rechargeable batteries, zinc stands out due to its extremely high theoretical volumetric capacity (5855 mAh cm⁻¹). -3 ), lower redox potential (Zn) 2+ Zinc secondary batteries based on polymer gel electrolytes (Zn, -0.76 V vs. SHE) stand out due to their non-toxicity and abundant zinc resources. Among them, organic polymer gel electrolytes have the greatest development potential due to their excellent safety and mechanical properties. However, zinc secondary batteries based on polymer gel electrolytes still face challenges in practical applications due to the presence of Zn. 2+ The slow diffusion rate and severe interfacial side reactions are major challenges, leading to significant electrode / electrolyte interface reactions that easily induce dendrite growth and cause short circuits. Therefore, designing an electrolyte with rapid zinc-ion transfer kinetics and a stable phase interface is crucial for achieving long-term stable operation of zinc-ion batteries. In polymer solid-state electrolytes, zinc-ion transport is mainly via Zn... 2+ This is achieved through repeated coordination and decoordination with the polar groups of the polymer segment.

[0003] In recent years, a series of polymer electrolytes, including polyethylene oxide, polyvinylidene hexafluoropropylene, polyacrylic acid, and polyacrylonitrile, have been successfully applied in zinc-ion batteries. For example, Chinese patent application CN113972408B discloses a zinc-based battery gel polymer electrolyte and its preparation and application. This is achieved by dissolving sodium alginate, polyvinyl alcohol, and polyvinylpyrrolidone in deionized water under heating conditions, followed by static and freeze-thaw cycles to form a uniform hydrogel. This hydrogel is then immersed in zinc salt and lithium salt electrolytes to prepare a gel polymer electrolyte with high mechanical strength and good flexibility. However, zinc-ion full batteries assembled with this gel electrolyte can only cycle 1000 times at 1C rate at room temperature, with a capacity retention of only 70%, indicating a significant gap from industrial application. Summary of the Invention

[0004] The purpose of this invention is to provide a zinc secondary battery gel polymer electrolyte and its preparation, as well as a zinc secondary battery, which can solve the problem of thermodynamic stability at the interface between metallic zinc and electrolyte, improve the low conductivity and transport number of zinc ions in solid-state zinc-ion batteries, and enhance the cycle stability of zinc secondary batteries.

[0005] The objective of this invention can be achieved through the following technical solutions: In a first aspect, the present invention provides a zinc secondary battery gel polymer electrolyte, which is formulated from zinc salt, organic solvent with a boiling point exceeding 100°C, polymer additives and fillers as raw materials.

[0006] Furthermore, the zinc salt is selected from one or more of the following: zinc trifluoromethanesulfonate (Zn(OTf)2), zinc acetate (Zn(CH3COO)2), zinc trifluoroacetate (Zn(CF3COO)2), zinc bis(trifluoromethanesulfonyl)imide (Zn(TFSI)2), zinc trifluoromethanesulfonate (Zn(TFSI)2), zinc bis(fluorosulfonyl)imide (Zn(FSI)2), zinc tetra(hexafluoroisopropoxy)borate (Zn(BHFip)2), zinc chloride (Zn(Cl)2), zinc sulfate (ZnSO4), zinc nitrate (Zn(NO3)2), zinc perchlorate (Zn(ClO4)2), N-(benzenesulfonyl)benzenesulfonamide zinc (Zn(BBI)2), and zinc fluoroborate (Zn(BF4)2).

[0007] Furthermore, the organic solvent is one or more of N-methylformamide (NMF), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), N-methylpyrrolidone (NMP), trimethyl phosphate (TMP), triethyl phosphate (TEP), dimethyl sulfoxide (DMSO), sulfolane, diethylene glycol dimethyl ether (DEGDME), diethylene glycol diethyl ether (DEGDEE), dipropylene glycol dimethyl ether, dipropylene glycol dimethyl propyl ether (DPGDME), butyl acetate, ethyl butyrate, butyl butyrate, propylene glycol methyl ether acetate, 3-methoxybutyl acetate, 2-ethoxyethyl acetate, methyl acetoacetate, and ethyl acetoacetate.

[0008] Furthermore, the polymer additive includes one or more of the following: polyethylene oxide (PEO), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polyacrylic acid (PAA), polymethyl methacrylate (PMMA), polyimide (PI), polyacrylonitrile (PAN), polyphenylene ether (PPO), poly(2,2'-disulfonyl-4,4'-benzidine-terephthalamide) (PBDT), polymalonate (PME), polyethylene glycol succinate (DEGS), and poly(β-propiolactone) (PPL). Specifically, its molecular weight is 50,000 to 1,000,000.

[0009] Furthermore, the filler is one or more of fumed silica (SiO2), aluminum oxide (Al2O3), titanium dioxide (TiO2), magnesium oxide (MgO), graphene oxide (GO), barium sulfate (BaSO4), and calcium carbonate (CaCO3). Specifically, its particle size or thickness is 5-500 nanometers.

[0010] Furthermore, the ratio of zinc salt, organic solvent, polymer additive to filler is (1-20) mmol : (10-50) mL : (0.5-10) g : (0.01-1) g.

[0011] In a second aspect, the present invention provides a method for preparing a zinc secondary battery gel polymer electrolyte, comprising the following steps: S1. Dissolve the zinc salt and polymer additives in an organic solvent and stir continuously until a homogeneous and transparent solution A is formed; S2. Disperse the filler in an organic solvent under ultrasonic assistance to obtain solution B; S3. Add solution A from S1 to solution B from S2, mix well and heat and stir to obtain a sol-like product, then coat it on the surface of the membrane and vacuum dry to obtain a gel polymer electrolyte membrane.

[0012] Furthermore, the heating and stirring temperature is 20~80℃.

[0013] Furthermore, in S3, the thickness of the sol-like product coated on the diaphragm surface is 50~200μm; The thickness of the polymer electrolyte membrane is 5~100μm.

[0014] In a third aspect, the present invention provides the application of a zinc secondary battery gel polymer electrolyte in the preparation of novel secondary batteries.

[0015] Furthermore, in application, it is coated onto the surface of a diaphragm and dried to form an electrolyte membrane. Preferably, the thickness of the polymer electrolyte membrane is 5~100 μm.

[0016] In a fourth aspect, the present invention provides a zinc secondary battery, comprising a positive electrode, a negative electrode, a separator, and a zinc secondary battery gel polymer electrolyte as described in the first aspect above coated on the surface of the separator.

[0017] Furthermore, the positive electrode is an organic positive electrode or a composite positive electrode of an organic positive electrode and a metal oxide or phosphate, and the negative electrode is zinc metal.

[0018] Furthermore, the positive electrode is prepared through the following process: p-Chloroquinone and sodium sulfide nonahydrate were dissolved in a mixed solution of ethanol / water at a molar ratio of 1:4 to 4:1 (v / v) and the mixture was stirred at 80 °C for 1 to 12 hours. Subsequently, a DMF solution containing p-chloroquinone (0.1 to 5 mol / L) was added to the system. -1 The mixture was refluxed for 10 hours. After the reaction was complete, the precipitate was collected by filtration and washed successively with DMF, water and ethanol to finally obtain tetrachloro-p-benzoquinone (PTClQ) powder.

[0019] The positive electrode material was prepared by mixing PTClQ, Super P, acetylene black, and a binder in a mass ratio of 4:2:2:2. The binder was prepared by mixing sodium carboxymethyl cellulose and styrene-butadiene rubber in a mass ratio of 2:1. The above powders were thoroughly ground in a mortar until uniformly mixed, and then an appropriate amount of water was added to form a homogeneous slurry. This slurry was uniformly coated onto a titanium foil current collector to prepare the working electrode. The coated electrode was dried under vacuum at 60 °C for 12 hours to remove residual solvent. After drying, the electrode was cut into a disc with a diameter of 10 mm using a precision die. The final measured active material loading of the electrode was approximately 1~1.5 mg cm⁻¹. -2 .

[0020] Compared with the prior art, the present invention has the following advantages: (1) In polymer gel electrolytes, the physical cross-linking between polymer molecules can improve the flexibility of the electrolyte membrane. At the same time, the functional groups (cyano, hydroxyl, etc.) in the polymer molecular chain can anchor zinc ions through coordination. Nanoscale inorganic fillers promote the rapid transfer of zinc ions while improving the disorder of the material. The polymer electrolyte membrane and the zinc anode have a stable thermodynamic interface, which can promote the repeated deposition and stripping of zinc metal on the anode surface, effectively avoiding the formation of zinc dendrites.

[0021] (2) The polymer gel electrolyte prepared by the method provided in this invention can stabilize the electrode / electrolyte interface and improve the electrochemical performance of the battery. When this gel electrolyte is applied to a zinc-ion battery, at a current density of 3 mA cm⁻¹, it achieves good performance. -2 Under these conditions, the assembled zinc-zinc symmetric cell can achieve a cycle life of over 5330 hours. At 5 mA cm⁻¹ -2 Even at high current densities, it can still achieve stable operation for 1850 hours. Furthermore, this battery exhibits a wide electrochemical window (≈2.7 V vs. Zn). 2+ The high coulombic efficiency of 99.997% (Zn) indicates that the battery assembled with this polymer electrolyte membrane exhibits excellent cycle stability. Compared with other patents, this technology enables ultra-long stable operation of zinc secondary batteries, with a lifespan far exceeding that of other patented methods.

[0022] (3) Compared with traditional gel polymer membrane preparation methods, this preparation method can be carried out under milder conditions and does not require large-scale instruments and equipment. The preparation process is simple: the polymer, zinc salt and inorganic filler are dissolved in N,N-dimethylformamide solution in a certain proportion to obtain a gel polymer solution. The polymer solution is coated on a commercial polyethylene membrane, and a polymer electrolyte membrane with adjustable thickness can be obtained by controlling the loading and drying under vacuum heating.

[0023] (4) Compared to other methods, the polymer gel electrolyte membrane prepared by this method exhibits rapid zinc ion transport kinetics and strong mechanical strength, which can effectively suppress dendrite formation and improve the long-term cycling stability of the zinc metal anode. The polymer gel electrolyte membrane prepared by this method has high Zn content. 2+ The transfer number can reach approximately 0.8, and the room temperature ionic conductivity can reach 1.8 × 10⁻⁶. -3 S cm -1 about. Attached Figure Description

[0024] Figure 1 Scanning electron microscope image and photograph of the gel electrolyte membrane prepared in Example 1; Figure 2 Stress-deformation rate curves of the gel electrolyte membranes prepared in Example 1 and Comparative Example 1; Figure 3 The ionic conductivity diagrams are for the samples prepared in Example 1, Comparative Example 1, and Comparative Example 2. Figure 4 The zinc ion transport number diagrams are for the samples prepared in Example 1, Comparative Example 1, and Comparative Example 2. Figure 5 The samples of Example 1, Comparative Example 1, and Comparative Example 2 were subjected to a current density of 3 mA cm⁻¹. -1 The following is a graph showing the cycle stability test results of a Zn||Zn symmetric battery; Figure 6 The samples of Example 1, Comparative Example 1, and Comparative Example 2 were subjected to a current density of 5 mA cm⁻¹. -1 The following is a graph showing the cycle stability test results of a Zn||Zn symmetric battery; Figure 7 The graph shows the coulombic efficiency of the samples from Example 1, Comparative Example 1, and Comparative Example 2 as a function of the number of cyclic test cycles. Figure 8 The full-cell rate performance graph for the sample assembly of Example 1; Figure 9 The graph shows the full-cell cycle stability test results of the sample assembly in Example 1. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0027] As used herein, the terms "and / or," "or / and," and "and / or" encompass any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected using at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that, in this application, the technical solution undoubtedly includes solutions connected by "logical AND," and also undoubtedly includes solutions connected by "logical OR."

[0028] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0029] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0030] This document only specifically discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0031] Unless otherwise specified, the temperature parameters in this application may be either constant temperature processing or processing within a certain temperature range. The constant temperature processing allows temperature fluctuations within the precision range controlled by the instrument, such as ±5°C, ±4°C, ±3°C, ±2°C, or ±1°C.

[0032] In this document, the term "suitable" as used in phrases such as "suitable combination," "suitable method," and "any suitable method" refers to the ability to implement the technical solution of this application, solve the technical problem of this application, and achieve the expected technical effect of this application.

[0033] In this application, terms such as "further," "even more," and "particularly" are used for descriptive purposes and to indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0034] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0035] In the description of the application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] Unless otherwise specified, all preparations and tests described herein took place at 25°C.

[0037] The terms “comprising,” “including,” “containing,” “having,” “comprising,” or other variations thereof are intended to cover non-closed inclusion, and no distinction is made between these terms. The term “comprising” means that other steps and ingredients may be added without affecting the final result. The compositions and methods / processes of the present invention comprise, consist of, and substantially consist of the essential elements and limitations described herein, as well as any additional or optional ingredients, components, steps, or limitations described herein. No distinction is made between the terms “efficacy,” “performance,” “effect,” and “potency” herein.

[0038] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of this application can be combined to form new technical solutions.

[0039] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, but sequentially is preferred.

[0040] The polyethylene diaphragm was purchased from Shanghai Songjing New Energy Co., Ltd., model Celgard 2400, with a thickness of approximately 25 micrometers.

[0041] Example 1 1 g of zinc trifluoromethanesulfonate and 1 g of polyacrylonitrile (weight-average molecular weight 150,000) were successively dissolved in 20 mL of N,N-dimethylformamide solution and magnetically stirred at room temperature for 12 hours until completely dissolved. 40 mg of fumed silica (average particle size approximately 12 nm) was dispersed in 20 mL of N,N-dimethylformamide and slowly added to the above solution. The solution was coated onto a commercial polyethylene membrane (approximately 25 μm thick) to a thickness of 100 μm. After vacuum drying at 60°C for 24 hours, a polymer electrolyte membrane with a thickness of approximately 50 μm was obtained.

[0042] Example 2 1 g of zinc trifluoroacetate, 0.5 g of polyacrylonitrile (weight-average molecular weight 150,000), and 0.5 g of polyethylene oxide (weight-average molecular weight 600,000) were successively dissolved in 15 mL of dimethyl sulfoxide solution and magnetically stirred at room temperature for 12 hours until completely dissolved. 20 mg of fumed alumina (average particle size approximately 50 nm) was dispersed in 15 mL of N,N-dimethylformamide and slowly added to the above solution. The mixture was coated onto a commercial polyimide membrane (approximately 25 μm thick) to a thickness of 100 μm. After vacuum drying at 60°C for 24 hours, a polymer electrolyte membrane with a thickness of approximately 60 μm was obtained.

[0043] The electrolytes prepared in the above embodiments or comparative examples were used to assemble zinc-ion batteries and their performance was tested, as detailed below.

[0044] The preparation method of the positive electrode material used is as follows: 5 mmol of p-chloroquinone and 20 mmol of sodium sulfide nonahydrate were dissolved in a mixed solution of 40 mL of ethanol and 50 mL of water, and the mixture was stirred at 80 °C for 12 hours. Then, 30 mL of N,N-dimethylformamide solution containing 5 mmol of p-chloroquinone was added to the system, and the mixture was refluxed for 10 hours. After the reaction was complete, the precipitate was collected by filtration and washed successively with N,N-dimethylformamide, water, and ethanol to obtain a black, highly active material.

[0045] The positive electrode material is prepared by mixing black active material, Super P, acetylene black, and binder in a mass ratio of 4:2:2:2. The binder is composed of sodium carboxymethyl cellulose and styrene-butadiene rubber in a mass ratio of 2:1. The above powders are thoroughly ground in a mortar until uniformly mixed, and then an appropriate amount of water is added to form a homogeneous slurry. This slurry is uniformly coated onto a titanium foil current collector to prepare the working electrode. The coated electrode is dried under vacuum at 60 °C for 12 hours to remove residual solvent. After drying, the electrode is cut into 10 mm diameter discs using a precision die. The assembly and testing method for Zn||Zn symmetric cells is as follows: Battery assembly was conducted in a glove box with oxygen content below 0.1 ppm and water content below 0.1 ppm. Zn||Zn symmetric cells were assembled using CR2016 button cells. The zinc foil was 100 μm thick and 12 mm in diameter. The gel electrolyte membrane used was approximately 50 μm thick. Battery performance during cyclic charge-discharge was evaluated using a battery testing system (LAND, CT2001). Zn||Zn symmetric full cells were tested within a voltage range of 1.6 V to 0.2 V. Linear sweep voltammetry was performed using electrochemical workstations (Solartron analytics 1400 and Solartron analytics 1470E).

[0046] The methods for assembling and testing Zn||Cu half-cells are as follows: Battery assembly was conducted in a glove box with oxygen and water content below 0.1 ppm. Zn||Cu half-cells were assembled using CR2016 button cells. The zinc anode was a 100-micrometer-thick, 12-millimeter-diameter zinc foil, and the copper anode was a 100-micrometer-thick, 12-millimeter-diameter copper foil. The gel electrolyte membrane used was approximately 50 micrometers thick. Battery performance during cyclic charge-discharge was evaluated using a battery testing system (LAND, CT2001). The Zn||Cu half-cells were tested within a voltage range of 1.6 V to 0.2 V. Linear sweep voltammetry was performed using an electrochemical workstation (Solartron analytics 1400 and Solartronanalytics 1470E).

[0047] The assembly and testing methods for Zn||PTClQ full cells are as follows: Battery assembly was conducted in a glove box with oxygen content below 0.1 ppm and water content below 0.1 ppm. Zn||PTCIQ full cells were assembled using CR2016 button cells. The zinc anode was a 100-micrometer-thick zinc foil with a diameter of 12 millimeters. The tetrachloro-1,4-benzoquinone (PTCIQ) cathode had a diameter of 12 millimeters, and the gel electrolyte membrane used was the polymer electrolyte membrane prepared in the above examples or comparative examples. Battery performance during cyclic charge-discharge was evaluated using a battery testing system (LAND, CT2001). The Zn / / PTCIQ full cells were tested within a voltage range of 1.6 V to 0.2 V. Linear sweep voltammetry was performed using electrochemical workstations (Solartron analytics 1400 and Solartron analytics 1470E).

[0048] like Figure 1 As shown, the surface of the gel polymer electrolyte membrane prepared in Example 1 is uniform and smooth, with no obvious pores.

[0049] like Figure 2 As shown, the gel polymer electrolyte membrane prepared in Example 1 has good flexibility and can withstand a maximum tensile force of 112.73 MPa without significant deformation.

[0050] like Figure 3 As shown, the ionic conductivity of the gel polymer electrolyte membrane prepared in Example 1 is 1.79 × 10⁻⁶. -3 The S / cm ratio is significantly higher than that of the gel electrolyte membrane prepared in Comparative Example 1 (0.35 × 10⁻⁶). -3 The conductivity (S / cm) is 0.55 × 10⁻⁶, the same as that of the liquid electrolyte prepared in Comparative Example 2. -3 Conductivity in S / cm.

[0051] like Figure 4 As shown, the zinc ion migration number of the gel electrolyte membrane prepared in Example 1 is 0.75, which is much higher than the migration number of 0.42 of the gel electrolyte membrane prepared in Comparative Example 1 and the migration number of 0.28 of the liquid electrolyte prepared in Comparative Example 2.

[0052] like Figure 5 As shown, in a Zn||Zn symmetric cell, at a current density of 3 mA cm⁻¹ -2 Under these conditions, the battery based on the electrolyte membrane of Example 1 can operate stably for 5330 hours.

[0053] like Figure 6 As shown, in a Zn||Zn symmetric cell, at a current density of 5 mA cm⁻¹ -2 Under these conditions, the battery based on the electrolyte membrane of Example 1 can operate stably for 1850 hours.

[0054] like Figure 7 As shown, in a Zn||Cu half-cell, at a current density of 0.5 mA cm⁻¹ -2 In the case of the electrolyte membrane of Example 1, the average coulombic efficiency of the battery was 99.89% from the first to the third 3000 cycles, and 99.98% from the fifth to the third 3000 cycles.

[0055] like Figure 8 As shown, in a Zn||PTClQ full cell, from 0.1 to 1 A g -1 The specific capacities within the current density range were 139.56, 111.20, 65.43, 54.01, 63.69, 73.82, 97.32, and 96.67 mAh g, respectively. -1 This indicates that the full cell based on the electrolyte membrane of Example 1 has high rate performance.

[0056] like Figure 9 As shown, in a Zn||PTClQ full cell, at a rate of 0.1C, the initial capacity of the battery based on the electrolyte membrane of Example 1 is 143 mAh g⁻¹. -1 It can still maintain a specific capacity of 97.39% after more than 500 cycles.

[0057] Comparative Example 1 (Polymer electrolyte membrane without filler) 1 g of zinc trifluoromethanesulfonate and 1 g of polyacrylonitrile (weight-average molecular weight 150,000) were successively dissolved in 20 mL of N,N-dimethylformamide solution. The solutions were magnetically stirred at room temperature for 12 hours until completely dissolved. The resulting solution was then coated onto a commercial polyethylene membrane (approximately 25 μm thick) to a thickness of 100 μm. After vacuum drying at 60°C for 24 hours, an unfilled polymer electrolyte membrane was obtained.

[0058] Comparative Example 2 (Conventional Electrolyte) 1.8 g of zinc trifluoromethanesulfonate was dissolved in 10 mL of N,N-dimethylformamide solution and magnetically stirred at room temperature for 12 hours until completely dissolved to prepare a 0.5 M electrolyte. The diaphragm was a commercially available polyethylene diaphragm with a thickness of approximately 25 micrometers.

[0059] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A zinc secondary battery gel polymer electrolyte, characterized in that, It is formulated from zinc salts, organic solvents with boiling points exceeding 100°C, polymer additives, and fillers.

2. The zinc secondary battery gel polymer electrolyte according to claim 1, characterized in that, The zinc salt is selected from one or more of zinc trifluoromethanesulfonate, zinc acetate, zinc trifluoroacetate, zinc bis(trifluoromethanesulfonyl)imide, zinc trifluoromethanesulfonate, zinc bis(fluorosulfonyl)imide, zinc tetra(hexafluoroisopropoxy)borate, zinc chloride, zinc sulfate, zinc nitrate, zinc perchlorate, zinc N-(benzenesulfonyl)benzenesulfonamide, and zinc fluoroborate.

3. The zinc secondary battery gel polymer electrolyte according to claim 1, characterized in that, The organic solvent is one or more of N-methylformamide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, trimethyl phosphate, triethyl phosphate, dimethyl sulfoxide, sulfolane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol dimethyl propyl ether, butyl acetate, ethyl butyrate, butyl butyrate, propylene glycol methyl ether acetate, 3-methoxybutyl acetate, 2-ethoxyethyl acetate, methyl acetoacetate, or ethyl acetoacetate.

4. The zinc secondary battery gel polymer electrolyte according to claim 1, characterized in that, The polymer additives include one or more of polyethylene oxide, polyvinylidene fluoride-hexafluoropropylene, polyacrylic acid, polymethyl methacrylate, polyimide, polyacrylonitrile, polyphenylene ether, poly(2,2'-disulfonyl-4,4'-benzidine terephthalamide), polymalonate, polyethylene glycol succinate, and poly(β-propiolactone).

5. The zinc secondary battery gel polymer electrolyte according to claim 1, characterized in that, The filler is one or more of the following: fumed silica, aluminum oxide, titanium dioxide, magnesium oxide, graphene oxide, barium sulfate, and calcium carbonate.

6. The zinc secondary battery gel polymer electrolyte according to claim 1, characterized in that, The ratio of zinc salt, organic solvent, polymer additives and filler is (1-20) mmol: (10-50) mL: (0.5-10) g: (0.01-1) g.

7. The method for preparing the zinc secondary battery gel polymer electrolyte according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Dissolve the zinc salt and polymer additives in an organic solvent and stir continuously until a homogeneous and transparent solution A is formed; S2. Disperse the filler in an organic solvent under ultrasonic assistance to obtain solution B; S3. Add solution A from S1 to solution B from S2, mix well and heat and stir to obtain a sol-like product, then coat it on the surface of the membrane and vacuum dry to obtain a gel polymer electrolyte membrane.

8. The method for preparing the zinc secondary battery gel polymer electrolyte according to claim 7, characterized in that, In S3, the thickness of the sol-like product coated on the diaphragm surface is 50~200μm; The thickness of the polymer electrolyte membrane is 5~100μm.

9. The application of the zinc secondary battery gel polymer electrolyte as described in any one of claims 1-6 in the preparation of novel secondary batteries.

10. A zinc secondary battery, characterized in that, It includes a positive electrode, a negative electrode, a separator, and a zinc secondary battery gel polymer electrolyte as described in any one of claims 1-6 coated on the surface of the separator.

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